The Sonic and the Sacrifice
by angelinabeanie92
Summary: He's tracking a deadly alien across the galaxy. She's fighting a god. Are they the same? The Doctor teams up with the Slayer for the fight of their life. Takes place shortly before the tenth doctor's regeneration and during season five of Buffy
1. Chapter One

Chapter one

She already had one of the worst days of her life and now this? first the announcement of the watchers council was making a visit to gauge her abilities in order to make sure that she could protect her sister-the key-not that they knew who she was, of course. then Glory into her home and proceeded to drone on about how she could squash Buffy like a bug, but knights? What else was the world going to throw at her?

She had failed the assessment, her friends were being watched and to top it all off, knights! Legitimate knights clad in medieval armor! It was a tactical advantage for her, but Buffy found that no matter how many times she knocked them down they just sprung up, and more appeared.

Armed only with a stake, she was stressed, exhausted, and they had her backed into a corner. Dawn was home safe, guarded by Spike, and the rest of the Scoobies were waiting for her. she couldn't let them down, but it felt like the weight of the world was on her shoulders.

Part of her wanted to take Dawn and her family and run. But nowhere on the planet was safe. Glory would find them, and failure seemed imminent. She scanned her surroundings, braced herself for whatever the knights threw at her. She knew that she was in a tight spot and she was outnumbered. she took a step back trying to keep distance between them while fighting.

her hands brushed something that wasn't the wall that was there a few seconds ago. Her small alley had disappeared. Instead she stood in a grungy, organic room. tall tree like curved structures surrounded her and when she turned around, she found herself face-to-face with a tall man in a brown suit.

"No, no!" He yelled. "I told you! No more people!" The center of a buffy assumed was some sort of control console _whorped_ in response. "Okay, fine!" He responded and then turned to the blonde who wore a puzzled expression on her face. He half-waved. "Hello!" He grinned. "I'm The Doctor. Sorry about that! She has a mind of her own."

"You're British."

"And you're not. Been a while since I've had an American passenger. Where'd I pick you up?"

"Sunnydale, California."

He peered at her over his square rimmed glasses.

"Judging by your clothes, early 21st century, right?"

"Last I checked." Buffy answered. She moved closer to him, sizing him up, ready to defend if need be. "Look don't take this personally, but I've had a lot of bad luck with British guys. I don't know who, or what you are, but I'm really tired of guys in suits screwing with my life."

"What do you mean 'what'"

The blonde rolled her eyes a slight smile playing at her lips. She reached into her inner jacket pocket and retrieved her stake.

"Vampire Slayer." She answered. "I'm Buffy."

"No!" He jumped up and pulled out a silver device glowing blue at the end. He waved it in the air in front of her. Buffy give him a puzzled look as he rushed around the console all while talking a million miles an hour. "I mean I've heard of you, but I thought you were just a myth. One girl in all the world to save the world, kind of seems impossible but then again I'm here and…"

before he could say anything else, he felt fist collide with the left side of his face. He fell backward landing on his arm which cracked.

"I need to get back."

"Blimey you hit hard!" His body glowed as he healed himself. "A word of advice, if you want somebody to do something for you, you don't hit!" His regeneration didn't even phase her. "My ship brought me to you, and I'm assuming it has something to do with the knights you were fighting. Who are they? And what did they want with you?"

"You wouldn't believe me if I told you." She said dryly.

"I just healed myself and used excess regeneration energy right in front of you and you didn't even blink. I think I can handle it. Try me."

"What are you doing here? And where is here?"

Wherever she was, it was some sort of ship. Possibly a spaceship if she believed in that. The whole scene was magnificent. the room never seemed to end and everywhere she looked she found something different to catch her interest.

"I told you, the TARDIS." He maneuvered around to the other half of the console and pulled monitor towards him. "it stands for Time and relative dimension in space. I was tracking this creature hidden in human form. You might call her Glory. Impossible to kill, but if I can send her back home, I can save the world... Again."

"You sound like me." Buffy half smiled. "Did you just say Glory?"

"That's what she calls herself. Damn near impervious to harm. But she's got this cloaking mechanism... Well sort of. Not really. You might not understand. I'm going to say you might not understand but I know that you wouldn't."

"People smack you a lot, don't they?"

"Yeah, don't know why."

"I have a few ideas."

She moved towards the doors and before he could stop her, she had them open. Whatever was outside, it wasn't Sunnydale. Instead a vast expanse of purple, blue, pink, and orange greeted her. Stars twinkled all around her and in the distance was the outline of her solar system. She stepped back and gasped.

The doctor scratched his head nervously.

"I believe I mentioned that this is a spaceship."

"Yeah. I didn't believe you. I need to go home."

"Right." He smiled. "You said Sunnydale right? Hold that button."

Buffy pressed it down as the doctor ran around the console flipping various switches. The tardis jerked, throwing her forward and then came to a halt.

"There you go. About two minutes after you left. Same spot too, judging by the sound of things."

Buffy took a deep breath and turned towards him.

"You might wanna stay back. This is gonna get messy."

The Doctor nodded and waited for her to leave. As soon as it was clear, he did a scan. She was outnumbered, and if he didn't do something, she was going to die. He set his sonic up and left the TARDIS. They were locked in battle, but he had to admit she moved well. He pointed to Sonic at the gutters of the building closest to her and pressed the button. They landed with a crash on top of the knights pinning them to the ground, and giving Buffy an opportunity to regain composure.

She kicked the sword out of the leader's hand, picked it up and pressed it to his throat.

"I've had a bad day." She jammed her foot into his ribcage. "Give me one reason why I shouldn't kill you."

"You cannot stop us." He twitched, attempting to move the gutters and half successful. The Doctor pushed the button again and the gutters on the adjacent row of buildings added to the weight.

"Pretty sure I can." She pressed harder with the sword, drawing blood.

Before she could speak, The joined Buffy. He stooped down and examined them. The markings on their forehead looked familiar.

"You're a long way from home." He muttered. "The Byzantium knights. You're billions of galaxies away. Why Earth?"

"We must stop the beast." He answered. "We cannot let it roam."

"What do you think I'm trying to do?"

"The Slayer guards the key. The key must be destroyed."

"Like hell it does!" Buffy gritted her teeth. She prepared to strike but The Doctor used the screwdriver to knock the sword out of her hands. She glared at him and wore _a what the hell do you think you're doing_ look.

"Sorry." He smiled sheepishly. "But they aren't human. That makes them my responsibility."

"What part of 'Vampire Slayer" do you not understand? Also what is that thing?"

"My sonic screwdriver!" He tossed it to her. "Always comes in handy."

"I gotta get me one of those." She admired the design and then chucked it back. "I mean I'm a little more medieval, but it may help someday." She softened her features. "Thank you by the way. Probably would have died had you not just appeared. But I've got to go face the music." She picked up the sword and took a deep breath.

Buffy opened the door under a sign that read 'the Magic Box' and he followed her in. She strode with purpose to the middle of a room lined with bookshelves filled with ancient volumes and various relics. Buffy placed the sword on the circular table in front of a stout British man wearing a crisp suit.

The Doctor hung back and took in his surroundings. He had just watched her fight a hoard of knights and not show a sign of fear. The man in the suit caused her face to tighten up, whether in fear or anger The Doctor couldn't tell. Above her a group of people in civilian clothes watched the scene unfold. On the ground floor, a handful of men and women in sharp suits stood with clipboards examining her every move.

"You're late." The stout one grumbled.

"I don't care." She sat down and looked him in the eye. She leaned forward, and fear flashed in his eyes. Buffy stood up and addressed the room.

"Everybody has been trying to take me down today. And I've been wondering why. But I figured it out. Power. I have it. They don't." She scanned the room making sure that every person understood what she was saying. "Glory came to my house today. She told me she could squash me like a bug. That I'm insignificant. But she didn't. Want to know why? Because I know what the key is. And she needs that from me."

The room grew deathly silent and the only sound was the rapid breathing of the suits.

"So here's how it's going to go. No interruptions. No tests. No interviews. No questions that you know I can't answer. No more following my friends." One of the women raised her finger to protest and without a second thought, Buffy flung the sword against the wall barely missing her. "I'm fairly certain that I said no interruptions."

The suit quieted and Buddy spoke again.

"You're watchers. Without a Slayer you're pretty much just watching masterpiece theater. You can't stop Glory. Hell, the only person who knows anything about her is him." Buffy pointed to The Doctor and he stepped up.

"Hello!" He waved. "I'm The Doctor." A man in a suit standing in the corner caught his attention. He looked at Buffy warmly, but his face resembled a foe fought before. "Contrary to what you may believe, she isn't what you think she is."

"We have it on the highest authority that-"

"You think I don't know what's in your libraries? You humans have such a small minds that you have to reason and rationalize by clinging to old myths! She's not a god. She's from another world. She damn near impossible to kill." he pulled up a seat and put his feet up on the table, interlocking his fingers behind his head. "She appears human, but she's not. She's got this sort of…cloaking mechanism. It's a lot like a perception filter. So if you're clever, and I am, you can see through it if you know what you're looking for."

"Can I talk now?" Buffy interrupted. "I wasn't done yet." She turned to the watcher in charge. "You know nothing. So here's how it's going to go. Giles will be my watcher again. He will be reinstated at full salary to be paid retroactively from the moment he was fired. And you? You will leave." She turned to The Doctor. "Go on."

Her leadership threw him off. People rarely took charge in his presence. He cleared his throat and picked up where he left off.

"Right. Glory has another half. A human half. Problem is that when a person sees her change, their memory is wiped. Find and destroy the human half, and glory is dead."

"But who is it?" Buffy asked.

"I couldn't tell you." The doctor said. "Glory has moved from world to world looking for the key to get home after she was banished for her crimes. Left a slaughter in her wake. She adapts to the customs and forms of each planet she inhabits." He then turned to the man who was watching Buffy so intently. "Do you have a brother?"

"Erm," he coughed. "No, why?"

"Fought an alien that looks just like you. Krillitane. Nasty creatures. Great at assimilating."

"Alien." He arched his brow. "But they don't exist."

"And yet here I am." The Doctor grinned. "I'm The Doctor."

"Doctor what?" The redhead on the balcony climb down the ladder and joined them. Then the rest of the entourage followed. "I'm Willow." She held out her hand. He shook it and grinned.

"Brilliant to meet you! And what a mind! You're just brewing with knowledge beyond what any human should know."

Willows cheeks flushed pink. A mousy brunette joined her, and they interlocked fingers.

"Are you magic too?" She asked. "I'm sensing something."

"More about me later. 22nd of May 2001 is our deadline. Judging by the air, it's March. That's two months to figure out who her other half is and for me to offer to take her back home so that she can face the penalty of her crimes."

"No." Buffy crossed her arms. "She has hurt too many people. If I find her, I will kill her."

"You can barely fight the knights right now." The Doctor retorted. "and you may have superhuman strength but that is no match for what she can do. She has destroyed planets and she won't stop."

"Excuse me." The female watcher spoke up. The group and the Doctor had forgotten that the watchers were still there. "The Doctor. The one who works for UNIT?."

"Yes. We don't have time to get into details. Well I mean I do, cause time travel, but you guys don't end it's hard to explain. And didn't Buffy dismiss you? If I were a human with human capabilities and one of, if not the strongest, person in the world was angry with me... I'd do what she says. Besides. I think I know more than what your puny library can provide."

Buffy nodded and they packed up, clipboards and all.

"That's better." He grinned. "I hate people with clipboards. Nothing good ever comes off a clipboard."

"So Doctor. Now that they're gone, who are you. You wanna help? I gotta trust you. Start from the beginning."


	2. Chapter 2

"I told you, I'm an alien." He answered.

"I don't believe that."

The doctor ran his fingers through his hair and stowed away his glasses. He pulled out his sonic and put it on the table for everybody can see. The eyed it curiously from a distance but said nothing.

"You watched me heal myself. I literally glowed. You can believe in vampires, witches, and demons, but you can't believe in aliens?"

He closed the space between Buffy and him. The rest of the Scoobies prepared to get between them if needed but Buffy held up a finger, stopping them. Reaching into his coat pocket, he retrieved a stethoscope. "Listen." He handed it to her, who fitted them into her ears.

"What am I listening to?"

The doctor guided her hand, first listening to the left side of the chest, and then moving it to the right. Their eyes met and he winked. Buffy dropped the stethoscope.

"Any more questions?" He addressed the group

"A lot, actually. How can we trust you?"

Before The Doctor could respond Buffy spoke

"He is, who, or what he says he is. And he saved my life. That's good enough for me." She looked him dead in the eye. "You're on probation."

"I've never been on probation before! This could be fun! Just let me lock up the TARDIS and I'll be right back." He left the way he came and paused at the blue doors. "One more fight." He muttered. "Let me have one more fight." He opened the door and entered, looking around. He hadn't had the body he had grown accustomed to long. His TARDIS kept the same interior longer than this regeneration

He shook the thoughts from his head and wound his way down the stairs to the library. He knew there was a volume on Glory, or, Glorificus as was her true name. He grabbed the book and made his way up to the console room. He turned with his back to the door, gazing lovingly at the place he had called home.

"I can't let her find you." He spoke. "When I lock this door, you need to leave. Go somewhere safe. The center piece _whorped_ in response. He pulled the doors closed and pressed his hand against the surface. "I'll see you later, old friend."

"Are you talking to a box?"

Buffy leaned against the wall surveying him.

"Well," The Doctor slid the key into its hole. "It's not just a box." He tossed her the volume and then turned the key. "Watch."

Right in front of her eyes, the box faded from view.

"Wait a second." A confused look crossed her features, as though trying to piece something together. "I came out of that thing. That's misleading. It's so much smaller on the outside."

"Usually it's the other way around, but yeah. Pretty much."

Buffy turned her attention to the book in her hands.

"What is this?" She opened it. "And why can't I read it?"

"Sorry. TARDIS translation matrix went when the TARDIS did. I can translate it to English but it'll take some time."

Buffy opened the door to the Magic Box and glanced back.

"You coming?"

The Doctor followed her into what appeared to be a training room. Weapon racks lined the brick walls and padding covered the floor. In the center of the room sat a saw horse, and a punching bag hung tucked in the corner. Buffy led him down a narrow hallway that opened up into the storefront. There Buffy's companions surrounded the circumference of the table which was piled high with books in various languages. Buffy cleared her throat.

"Guys, this is The Doctor. He's here to help." Buffy pointed at each individual. "You already met Willow. She's the brains of the group. Next to her is her girlfriend Tara." The mousy brunette gave him a shy smile. "Next we have Anya. She's attached to Xander and gives us Intel on the demonic world. Xander is next to her. And finally we have Giles." She gestured to the man The Doctor noticed earlier. "Giles is my Watcher."

"Hi, sorry about the Krillitane comment. Guess you had, well have, a duplicate. Time is wibbly."

"I'm not sure what a Krillitane is but I accept your apology."

The Doctor nodded in understanding.

"Right then. What have you got."

"Nothing." Xander said.

"Yeah, I'm with him." Willow agreed. She yawned. "It's late. And if she's an alien, then none of this will help."

"You'd be surprised." The Doctor said. He examined the pile of books left open. "Not every demon is a demon, Some have learned to adapt for survival and even mimic the behaviors of creatures." He slid the nearest book towards him. "The Kinderstat. German, you would think but they are a terrible race. Well it is, I should say. They produce axesually so there's only ever one. Kind of like the Loch ness monster. But it looks like you took care of it."

"Yeah, I was seventeen." Buffy pulled another book close to her "There's gotta be something that will help with Glory."

"Do you have a computer?" The Doctor asked as he picked up another book.

"I do." Willow piped up. "It's in my dorm room, though."

"Okay," Giles glanced at the clock mounted on the back wall "Well, Buffy I think you should get some sleep. Take the Doctor with you so that you aren't patrolling alone." At the look on Buffy's face he added "I know that you are more than capable of taking care of yourself but this Doctor chap is the only one who seems to know anything about Glory. Might be in your best interest to keep him alive."

"Fine." She pouted shrugging on her jacket. She tossed a stake to the brown clad man. "Your sonic won't help you against vampires."

The Doctor caught the stake and tucked it into his jacket pocket. Then he grabbed his sonic and placed it next to the stake.

"Let's go."

"So what's your deal?" She asked as they made their way down the street.

"What do you mean?" He kept in step with her.

"Well what planet are you from? Why are you helping me?"

"I'm from a planet called Gallifrey. I'm a Time Lord. The last of my species. I am nine-hundred-three years old. And to answer your last question humans never cease to amaze me with their resilience. Because of that, I will always help."

"Get down!" Buffy commanded, pushing him out of the way. He hit the ground. Buffy threw a punch at an incoming vampire. She ducked, took her stake and plunged it into the chest, leaving nothing but a pile of dust in its wake. She helped The Doctor up who wore a stunned expression on his face.

"Those weren't aliens." He mused. "Those were vampires, proper vampires! My mind is blown! This is fantastic! I've never seen anything like that! Well, I have but nothing like this. Usually there's some kind of transmat ray or something, but it's literally gone! I mean I've seen SATAN but this!" He kept pace with her running his fingers through is hair.

"Keep talking. You'll draw them to us." She warned. "We're almost home." Buffy added.

They turned into a suburban neighborhood. She paused, checking her surroundings.

"So what's it like being a vampire slayer?"

"Lonely." She answered. "I didn't ask for it, and I was supposed to be alone. Friends, family. This wasn't supposed to be for me. And I Have them…but I still feel so alone." They turned up the walkway and she climbed the steps. Pausing on the porch, she unlocked her door. "You'll have to be quiet. Mom and sis are asleep."

She pushed open the door and let him in. Laughter erupted to the right of them. Buffy went into the dining room to see Spike chatting with her mom. At the sight of her, he stood up abruptly.

"Hey. Mum and I were just talking. The nibblet is in bed and whos that?" His icy eyes fell on The Doctor. "He's not human.

"Neither are you." The Doctor quipped. "I'm the Doctor."

Spike turned to Buffy and eyed her curiously.

"Saved my life." She explained. "I could use something to drink. Is there hot water still?"

Joyce stood up and greeted the Doctor with a warm smile.

"I'm Joyce."

"Brilliant to meet you!" He grinned. "The family of the Slayer. Such an honor. Though I thought the slayer worked alone and, well we were just talking about it but this a lot to wrap my head around and that's saying something considering it's me and…"

"He does this a lot." Buffy shrugged moving into the kitchen. "Want some tea?" She called.

Spike followed The Doctor into the kitchen. He watched him carefully.

"What are you?" He asked

"Well that's a very rude question." The Doctor responded. "I'm a Time Lord. You?"

"Vampire."

Buffy pulled open the cupboard door.

"We don't have a lot of tea but you can make what you want." She stepped out of the way turning towards spike and fishing a twenty-dollar bill out of her pocket. "Thank you." She smiled slightly.

Spike shoved the money back at her.

"I didn't do it for the money. The kid is important." He turned to The Doctor. "Watch your step, Mate." Spike sauntered out the back door.

The Doctor poured his tea and added two spoonfuls of sugar.

"Do you have any milk?"

"Yeah, it's in the fridge." Buffy gesture vaguely. "Do you sleep? I can set up the couch for you."

"That would be lovely, thanks. I'll need a place to work on that translation as well."

"All I can offer is the living room when we're not at the Magic Box. Sorry I can't do more."

"Don't be." He grinned. "Have a lovely night."

He watched her climb the stairs as he sipped his tea. A wave of sadness washed over him but he didn't know why. Maybe it was because she reminded him of Rose. Her strength and ferocity with gentleness and kindness…

But Rose was gone. He could never see her again. And why would he? She was happy with the half-human timelord. The man he was…before. He thought of Donna and wondered how she was doing. If she was happy. His heart ached to see his best friend again but if she remembered…

Buffy descended the stairs carrying a pile of blankets. She handed them to him.

"Thank you." He smiled. "Get some rest."

She examined his face as though searching for something. A look of recognition flashed in her green eyes. For a second, they resembled Rose's.

"You okay?"

"Yeah, I'm fine. You should sleep."

She looked like she wanted to say something but then chose silence.

"Okay, good night."

He watched her again and blinked away a tear. Something was in the air. Something beyond Glory. Something bad. He just wish he knew what.


End file.
